As a tire is used, the tread of the tire tends to wear off. Sometimes it is desirable to attach a new tread onto the tire casing. The process of putting a new tread on a tire casing is known as retreading. In the process of retreading, it is necessary to grind or buff the rubber overlaying the belt of the tire, known as undertread, to a specific thickness, such as 3/32 (cm) of an inch, before attaching the new tread. Thus, an important step in the retreading process is measuring the thickness of the undertread.
Common problems often encountered in the art deal with the alignment of sensors on a buffer machine used to measure the undertread thickness. If the sensors are knocked out of alignment, for example, by a tire being mounted on a buffer machine, the operator has to realign the sensors. Also, a sequential alignment of the sensors may be desired. A sequential alignment is an alignment in which one sensor comes into operative association with the tire casing before another sensor. The prior does not disclose sequential alignment of sensors. Still another alignment problem is that sensors are displaced out of alignment when they are brought into operative association with a tire casing.
The present invention provides methods and apparatuses for measuring the undertread thickness using a sequencing, self-aligning mechanism. Thus, the alignment difficulties inherent in current undertread measuring apparatuses are overcome in a way which is simple and efficient, while providing better and more advantageous results.